1. Field of the Invention
The present invention relates to monolithic ceramic electronic components and methods for making the same. More particularly, the present invention relates to monolithic ceramic electronic components, such as monolithic inductors, monolithic capacitors, and monolithic LC composite components, and methods for making the same.
2. Description of the Related Art
In conventional noise suppression chip components, in order to ensure high impedance in the wide frequency range so that a noise reduction effect is achieved, for example, a component is fabricated by stacking a high-permeability magnetic layer and a low-permeability magnetic layer with a coil being disposed in each layer, and connecting the coils in series.
As an example of such a component, Patent Document 1, Japanese Unexamined Patent Application Publication No. 9-7835, discloses a monolithic inductor having a structure in which a high-permeability magnetic layer and a low-permeability magnetic layer are integrally laminated with a nonmagnetic intermediate layer therebetween. The nonmagnetic intermediate layer prevents interdiffusion between the material of the high-permeability magnetic layer and the material of the low-permeability magnetic layer, and prevents degradation in the magnetic properties of both magnetic layers.
Furthermore, Patent Document 2, Japanese Unexamined Patent Application Publication No. 6-232005, discloses a monolithic LC composite component having a structure in which a capacitor portion and a coil portion are composed of dielectric layers having different dielectric constants, and the dielectric layers having different dielectric constants are integrally laminated.
However, in the case in which a nonmagnetic intermediate layer is used as in the monolithic inductor of Patent Document 1, the bonding strength is lower compared with the case in which magnetic layers are directly bonded to each other. Furthermore, in order to obtain satisfactory bonding, the magnetic layers and the nonmagnetic intermediate layer must be adjusted to have the same shrinkage rate during firing, which requires troublesome processes and techniques. Furthermore, a new material for the intermediate layer must be prepared, which is one of the factors causing increases in manufacturing costs. The monolithic LC composite component of Patent Document 2 also has substantially the same problem.